1. Field of the Invention
The present invention relates to a sealed nonseparable cylindrical roller bearing, and in particular, to a sealed cylindrical roller bearing with improved sealing characteristics.
2. Description of the Prior Art
A prior art non-separable cylindrical roller bearing of this type is disclosed, for example, in Japanese Utility Model Laid-Open Publication No. 60-93015. This bearing, as shown in FIG. 1, includes an outer ring 1 having flanges 1a at opposite axial ends and serving as a raceway ring. An inner ring 2 includes a raceway ring 3 having a flange 3a at one axial end and includes a flange ring 4 in contact with an end face of a cylindrical roller 5. A seal plate 6 is fitted into a circular groove 1b at an axial end of the outer ring. The seal plate 6 includes a mandrel or core 7, and the inside end portion of the mandrel 7 is bent obliquely and inwardly, and an inside lip 8 extending inwardly in the axial direction from the inner edge of the mandrel 7 is slidingly in contact with an end face 4a of a step-formed portion of the flange ring 4. An outside lip 9 which extends from the inner edge of the mandrel 7 at right angles obliquely and outwardly in the axial direction is slidingly in contact with a cutout surface 4b at the step-formed portion of the flange ring 4.
In the cylindrical roller bearing described above, a problem arises in that when the flange ring 4 moves in the axial direction and in the radial direction during transportation, imparting an external force or shock to the inside lip 8 and outside lip 9 of the seal plate 6 by the flange ring 4, the inside lip 8 and outside lip 9 are damaged or worn and subjected to plastic deformation by the external force. As a result, the sealing function of the seal plate during use is impeded.
For this reason, it is necessary to secure the flange ring 4 against movement during transportation by using a special jig, which requires a great amount of labor and time to attach and remove.